1. Field of the Invention
The present invention relates generally to implement hitches and more specifically to hitches for towing two implements side-by-side in the field and one behind the other during transport.
2. Related Art
Hitches for increasing productivity by towing two or more individual implements in transversely spaced relation behind a tractor have become increasingly popular. To narrow the resulting unit for road transport, the hitches are designed to permit the implements to be towed one behind the other. Examples of such hitches are shown in U.S. Pat. Nos. 4,178,010; 4,213,628; 4,577,881; 4,875,527; and 5,024,456.
Many of the hitches that remain connected to the tractor during conversions do not permit in-line transverse positioning of the implements so that skips during turns and less convenient hopper filling are problems. The available hitches that require disconnection from the tractor during conversion between field-working and transport positions are inconvenient to work with, and several trips on and off the tractor are required to operate latches and make numerous connections and disconnections of hoses and electrical cables. A minimum of three or four unlatching and latching operations may be required for release and subsequent resecuring of the various hitch and brace structures during a conversion between field-working and transport positions.
Some hitches require a large space and several maneuvers, such as driving in a circle and reversing direction, to achieve the desired conversion. With those that have passive or freely swinging hitches, there is little control of the trailing implement during conversion between the transport and field-working positions. Therefore, conversions can result in a large area of packed wheel tracks and can be difficult, especially when the ground is soft, sloping or irregular and when the towed implements are carrying a substantial amount of grain or fertilizer.
On many of the available two-unit hitches, an additional relatively large rectangular frame is used with the forward hitch structure connected to the tractor. This frame often is heavy and unsightly and reduces clearance and accessibility near at least one front side of the structure. Side protruding hitch structure can limit close spacing of implements in the field-working position so that row spacing is adversely affected. With other hitches, manual movement of heavy hitch components may be necessary.